As for the card, it's a copy of Akroma's Will, an instant that lets you choose between all your creatures gaining flying, vigilance, and double strike, or lifelink, indestructible, and protection from each color until the end of the turn
A 2/1 vampire spirit that can't block for two mana, as long as an opponent has ten or less life, Bloodghast has haste
The mechanic can be quite powerful, but since Kaladesh and Aether Revolt, Energy hasnt received a ton of support
There are reasons, of course in the rare tournaments where Black Lotus is legal, it is an unmatched trump card, allowing a player to skip ahead to cast their most powerful spells on the first turn of a match